A virtual private network (“VPN”) is a private network that uses a public wide area network (“WAN”), such as the Internet, to securely connect remote sites or users together. Internet Protocol Security (“IPsec”) protocols may be used to establish mutual authentication between participants in a VPN connection, for example, between a security gateway and a peer. Participants may use the IPsec protocol suite and a two-phase Internet Key Exchange (“IKE”) protocol to establish a security association (“SA”) and associated tunnels for exchanging secure communications.
Current techniques for detecting a dead peer in a VPN are only applicable to phase I of the IKE protocol. Because more than one phase II tunnel may be associated with an IKE SA established in phase I, there is a need in the art for improved methods of detecting dead peers in VPN connections.